Thermostat control apparatus



Nov, 24, 1936. R, H. M AUTSCH THERMOSTAT CONTROL APPARATUS 4 Shee.tsSheet 2 Filed May 9, 1935 ZQZ iii: iivv mmmm IN ill," I

INVENTOR ROBERT HENRI MAUTS CH ATTORNEY Nov. 24, 1936. R MAUTSCH 2.0613 15? THERMOSTAT CONTROL APPARATUS Filed May 9, 19:55 4 sheets-sneer? INVEN'II'QOR ROBERT HENRI MAUTSCH ATTORN EY Patented Nov. 24, 1935 2,061,915 THERMOSTAT CONTROL APPARATUS Robert Henri Mautsch, Brussels, Belgium, as-

signor to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application May 9, 1935, Serial No. 20,571

a In Belgium September 26.1934

14 Claims. (Cl. 291-11 This invention relates to thermostatic control apparatus of the kind in which the expansion or contraction of a metallic element under the influence of variations in the temperature to which I the element is subjected is utilized to control the operatlonof any device to be thermostatically controlled and has for its object to provide improved apparatus of this character which shall be particularly sensitive and accurate in operation,unaflected by vibration and proof against damage by sudden considerable temperature V8.7 riations. v n

The improved apparatus of the invention is moreover adapted to provide a substantially linear regulating characteristic over a wide range of operating temperatures and by the elimination of articulated parts in the mechanism for amplifying the expansion .or contraction of the element, any inaccuracy due to lost motion or play is avoided while the adjustment of the apparatus for operation under various conditions is effected in a particularly simple and precise manner.

The invention is particularly although not exclusively applicable to apparatus for the control of electric circuits in which thermostatically operated contacts are required to be positively and reliably actuated under predetermined temperature conditions.

According to the principal feature of the invention one end of the metallic element is connected through a non-articulated joint to one end of an intermediate member the other end of which is similarly connected to a suitable point in a relatively non-expansible element, in such a manner that the expansion or contraction of the metallic element due to temperature variations causes a couple to be exerted upon the intermediate member the movement of which under the action of this couple is arranged to effect the desired control.

The invention is illustrated by way of example in the accompanying drawings, Figure l of which is a sectional view of a simple. form of thermostatic control apparatus embodying one form of the invention. Figure 2 being a diagrammatic view thereof illustrating its action. Figures 3, 4 and 5 are sectional views similar to Figure 1 but illustrating a construction embodying regulating and compensating arrangements, these figures showing the position oi the parts of the apparatus under different temperature conditions. Figure 6 is a view in side elevation of the complete apparatus shown in Figures 3, 4 and 5, Figure 7 being a similar view with the outer casing removed.

Figures 8, 9 and 10 are sectional views similar to Figures 3, 4 and 5 respectively but illustrating a somewhat modified construction.

Referring now first to Figures 1 and 2 of the drawings it will be seen that the apparatus comprises a metallic element in the form of a tube 1 provided with external heat radiating fins 2,;to the lower end of which is secured one end of a relatively non-expansible rod 3, coaxially arranged within the tube l. The upper end of the tube I. is connected by means of soldered joints indicated at 4 to the upper ends of metallic strips 5, the lower ends of which are connected by similar joints 6 to the lower ends of a pair of contact strips 1. Intermediate points in the strips 1 are secured by soldered joints 8 to the upper ends of a pair of strips 9, the lower ends of which are rigidly connected to the upper end of the rod 3 as indicated at HI. The upper ends of the strips 1 are provided with contact pieces II, I! adapted to cooperate to control an electric circuit which a in turn controls the operation of any desired device to be controlled. In this construction it will be understood that the portion of the strips 1 between the joints 6 and 8 constitutes the intermediate member hereinbefore referred to.

The operation of the apparatus is as iollows:-'-

Assuming that the parts occupy the positions shown in Figures 1 and 2 and that the apparatus is subjected to an increase in temperature, the tube 1 will expand relative to the rod 3 with the result that a pull, as indicated by the arrows l3 in Figure 2, will be exerted between the tube l and the rod 3, this pull being transmitted to the strips 5 and 9 through the joints 4 and Ill. The tension thus exerted on each of the strips 5 and 9 is transmitted through the joints 6 and 8 to the lower portion of each of the strips I constituting as above explained the intermediate member.

As clearly shown in Figure 2 the tension exerted on each of the strips 5 and 9 exerts a couple on the intermediate member tending to rotate the latter in a clockwise direction. As a result the upper portion of one of the strips 1, the lower portions of which constitute the intermediate member, will be moved'toward the right so as to cause the contact H carried thereby to engage with a corresponding contact 12 on the other contact strip 1, which is of course moved toward the left.

In Figure 2 the portion of the strip 1' constituting the intermediate member is indicated at I4 and it will be understood that the moment of the couple exerted upon this intermediate portion is dependent upon the distances A, B laterally separating the strips 5 and 9 from the strip I. The movement of the intermediate'member due to the couple above referred to will evidently cause anamplified movement of the upperv end of the strip I carrying the circuit contact,

the amplification being as shown in Figure 2 dependent upon the ratio of the distance D separating the contacts from the middle point of the intermediate member relative to the distances A and B.

It should be observed that the distances A and B need not as shown be equal to one another but may have any desired relation to suit particular requirements in practice, since'ii each oi the contacts II, l2 under the action of the couple on the intermediate member is moved through a distance equal to one-half of that normally separating these contacts, a still further amplification of the movement is obtained. Owing to the .fact that the couple effecting the actuation oi the 20 control contacts is due to the linear expansion of the tube I it will be evident that the apparatus has a linear operating characteristic in responseto temperature variations while the provision of the soldered joints between .the various parts which thus form a continuous mechanical linkage not involving any articulated joints, eliminates the possibility of any play or lost motion in the operation of the apparatus.

In practice it is round for instance'that with an aluminum tube I having a length of one meter the expansion of which is 0.000025 m. per degree C; increase in temperature, an amplification of forty times can readily be obtained. Assuming that the distance-separating the contacts I I, I2

is'l mm. so that a movement of 0.5 mm. is required to bring the contacts into. engagement with one another,this extent of movement will evidently be obtained for an increase in temperature oi the apparatusof 1 C. The normal distance separating the-contacts I I, I2 may however be reduced in practice to 0.2 mm. so that a movement of only 0.1 mm. for each contact is required and this movement will be effected by, an expansion of the tube l of 0.000005 in. corresponding to a temperature increase 01' only 0.2 C.

It will thus be seen that the apparatus can be arranged to operate with an extremely small temperature variation and is much more sensitive than any known form of thermostaticdevice." Furthermore by the vproi rision oi optical devices of any suitable type controlled by the movement of the strips I a much higher degree 01' sensitiv-" ity can be obtained as will ,be readily understood. Referring nowto Figures 3, 4 and 51in the construction therein shownthe'rod .3 is connected at its lower end to a stirrup member I8 with the interposition of a compression spring I8, the,

member I8 being secured to a rod 20, a spring 2| being interposed between a collar onv the rod 20 and an internal sleeve 22 secured by means oi! the screws 23 to the tube The lower end of the rod 20 is adapted, under certain conditions, i

to engage with a stop member 24'which is screwthreaded into a plug 25, the member v 24' being provided with a transverse pin 28 adapted to slide the sleeve 22 and is secured in position after adjustment by means or a set screw 29.

The pitch of the screw thread on the plug 2! is arranged to be difierent from the pitch of the screw thread on the lower end oi the stop mem-'- ber 24 so that by rotating the plug 25 by means of the knob 21 the position of the stop member 24 in the axial-direction within the sleeve 22 can be adjusted with a high degree of precision owing to the differential action of the two screw.

threads.

The action or the apparatus shown in Figures 3, 4 and is as follows:--

Figure 3' shows the parts 01' the apparatus in their normal adjustment for operation," it being observed that the control contacts II, I2 are separated by the normal distance required. Under these conditions the lower end of the-rod 20 is in contact with the upper end or the stop member 24, having been adjusted to this position by the rotation of the knob 21. J I e It, now, the apparatus is transferred to a space in which the temperature is higher than the temperature for which the apparatushad been ad iusted to its normal setting as shown in Figure 3, the expansion or the tube I will causea pull to be exerted upon the rod 3 through the intermediary or the sleeve 22, the spring 2| andthe stirrup member I8.

. The first part 01' this expansionmovement oi the tube I will cause the control contacts I], I2 to be moved into engagement with one another as shown in Figure .4 the further movement or the tube] effecting the compression of the spring 2|, and causingthe stop member 24 tomove out of engagement with the lower end or the rod 20 so that the parts assume the position shown in Figure 4. In order-to readjust the apparatus for the new temperature to rod 20 and to move this rod in an upward direction to permit the control contactsto resume their normal position shown in Figure 3.3 The set screw 29 -is then slackened and'the collar 28 is rotated relative to the plug 25 so as to bring a ,zero mark on the collar' opposite to a zero mark on the lower end of the sleeve 22. .The collar 20' I g which it is subjected the knob 21 is rotated so as to bring, the stop member 24 into engagement with the lower end or the a is then locked in itsadjusted position by means of a set screw'29 and the apparatus is in, readiness for operation at the new temperature.

11, on the other hand the apparatus when adiusted to-the position shown in Figure3'is transi'erred to aspace at'a' lower temperature the consequent contractionz'ofthe'tubei will cause.

member I8 to separate the control contacts to the position shown in Figure 5,;any iurthercontraction of: the tube I being taken-up by the compression oi! the spring l9.

. the stop member 24 to raise the rod; 20. and stirrup j In these circumstances, in order to the apparatus to the condiitons shown in. Figure'3,

theknob :21 must be rotated in the opposite direction tothat above described so as to move the stop member downwards and permit the rod 20 .to' move downwards under. the action of the spring 2| and after the spring I9 has been again expanded to its normal condition within the stirrup member I8 to allow the rod 3 to move downwards and restore the control contacts to the position shown inFigure 3.

Afterxthis adjustment has been effected the collar 28 is readjusted to its proper zone position as above explained. It will be understood that the compensating arrangements above described comprising the springs l9, 2| protect the .-sensltive parts or the apparatus against injury plug 15.

due to the apparatus being operated under widely diflerent temperature conditions irom time to time.

As shown in Figure with a number of graduations to the right and left its zero mark and it will be understood that once the apparatus has been set for the normal temperature or the space inwhich it is to be operated in the manner above described, a fine adjustment oi the control contacts can be eflected by rotating the knob 21 to an extent defined by the graduations on the collar 28. The apparatus can thus when adjusted in the manner above described be set to eflect the engagement of the control contacts for any desired small temperature variations the normal distance between the contacts being varied tor this purpose as will be apparent without further description. v

The tube I provided with this I as above described is preierably adapted to be enclosed in a perforated outer casing 30 as' indicated in Figure 6, suitable terminals 3|, 32 for the control circuit being provided as clearly shown in Figures 6 and '7. a

In the modification shown in Figures 8, 9 and i the stirrup member I8 is mounted in a sleeve forming the stop member 24, which is, as in the construction previously described with reierence to Figures 3, 4 and 5, adapted to be axially adjusted relatively to the tube I by means of the knob 21. i

Figure 8 corresponding to Figure 3, shows the parts of the apparatus in their normal adjustment for operation, Figures 9 and 10 on the other hand showing the abnormal position oi the parts for temperature conditions corresponding to those of Figures 4 and 5.

As shown in Figure 9 when the apparatus is removed to a higher surrounding temperature the stop sleeve 24 moves downwards with the tube I carrying with it the stirrup member I8 and compressing the spring 2|. As in the previous construction, in order to restore the parts to their previous normal adjustment, the knob 21 is rotated so as to move the stop sleeve 24 upwards and permit the stirrup member I8 to return to its normal position relative to the rod 3.

Under'the temperature conditions corresponding to Figure 10 the stop sleeve 24 has moved upwards with respect to the stirrup member I8 compressing the spring I9 and the restoration of the parts to the normal position is effected by rotating the knob- 21 in the reverse direction to that previously described as will be obvious without further explanation.

A spring 33-may be provided in order to prevent backlash between the stop 24 and the plug It will be apparent that the thermostatic control effected by the apparatus is dependent upon the temperature variations and consequently expansion or contraction to which the tube I as a whole is subjected and, since the dimensions of the tube I are considerable, the apparatus is not liable to be'aflected by small local draughts or air currents which would impair its proper operation. The rapidity oi-response of this thermostatic apparatus is very considerably increased by the provision oi ilns 2 on the tube I which greatly increase the area available for heat exchange.

It will be evident that the improved thermostatic apparatus of the invention may also be applied to other purposes than the control of electric contacts. For example the couple exerted upon the intermediate member may be ar- 7, the collar 28 is provided ranged to be transmitted through non-articulated amplifying mechanism similar to that above describedand illustrated to a needle or other type of valve controlling the flow oi fluid under pressure. The valve may for instance be a valve controlling the release of fluid from one side 0! a movable abutment so as to eflect. the movement of the abutment for operating any desired mecnanism.

The improved apparatus of the invention is particularly. suitable for use in controlling the temperature oirailway vehicles by reason mainly of its being unaffected by small local air curof example which may be varied in many respects without exceeding the scope of the invention.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: 1. In a thermostat, in combination, an element adapted to expand and-contract under the infinance-of variations of temperature to which the element is subjected, a control "member movable in directions transversely of the longitudinal center line 01' the element, and means connected by non-articulated joints to said element and,

control member operative upon the expansion or contraction of said element to actuate the control member.

2. In a thermostat, in combination, an element adapted to expand and contract under'the infiuence of variations of temperature to which the element is subjected, a control member, and means movable back and forth transversely of the longitudinal center line 01 the element connected to said element at the opposite ends of the control member by non-articulated joints and to said control element by non-articulated jqints, operative upon the expansion or contraction of said element to actuate the controlmember.

3. In a thermostat, in combination, an element adapted to expand and contract under the influence of variations of temperature to which the ment and control member, a force transmitting member secured to said control element at a point beyond the connection between the first mentioned iorce transmitting member and the control member and also secured to said element, said force transmitting elements cooperating to effect the operation of said control member when said element contracts or expands.

4. In a thermostat, in combination, an element adapted to expand and contract under the influence of variations of temperature to which the element is subjected, a movable control member, a force transmitting member secured at one end to one end of the control member and secured at the other end to said element, a force transmitting member extending in the opposite direction to the first mentioned force transmitting member and secured at one end to said control member at a point intermediate the ends of the control member and secured at the other end to said element, said force transmitting elements cooperating with said element and control meniadapted to expand and contract under the influence of variations of temperature to which" the; element is subjected, a movable control member, a force transmitting member secured at oneend to said element, a force transmitting member extending in the opposite direction to the firstmentloned force transmitting member and secured at one end to saidelement, and a yieldable non-articulated couple between the adjacent ends of said force, transmitting members and v control member for actuating the control mem- 6. In a thermostat, in combination, an element adapted to expand and contract under the influence of variations of temperature to which the element is subjected, a movable control mem- 20 members having their outer ends connected to said element and their innerends overlying each bar, two oppositely extending force transmitting other, and a yieldable non-articulated couple connecting the inner ends of said force transmitting members and the control member and operative to .eflect movement of the control member.

7. In a thermostat, in combination, an element adapted to expand and contract under the in-' fluence' of variations of temperature to which the element is subjected, a movable control member, a force transmitting member of less length than said element arranged substantially parallel with the element and connected at its outer end to 35 one end of the element, another force transmitting member of less length than said element arranged substantially parallel with the' element and connected'at its outer end to the element, and a yieldabie, non-articulated couple between the inner ends of said force transmitting members and the control member for eflecting movement of the control member according to the 1 forces set up in said force transmittingmembers;

UQ-In a thermostat, in combination, a metallic tube adapted to expand and contract in the direction of its length'under the influence of variations. of temperature to which the tube is subjected, a movable control member in said tube, a. force transmitting member in said tube and se- 59 cured at, its outer end to one end-oi the tube,

another force transmitting member in said tube and securedat its outer end to the other end of the tube, and a non-articulated couple between the inner ends of said force transmitting members and control member operable according to the forces applied thereto by said force transmitting members to effect the control movement spaced relation,

of the control member.

9. In a thermostat, in combination, a metallic tube adapted to expand and contract-in the direction of its length under the influence of variations of temperature to which the tube is sub'- jected, a movable control member in said tube, a force transmitting member in said tube, spaced from said control member and secured at its outer end to one end of the tube, means rigidly securing the inner ends of the control member and' force transmitting member together in another force transmitting -Iember in said tube spaced from said control clement and-secured at its outer-end to the other 'end of the tube, the'inner end of saidother force transmitting member overlying the inner ends of the control member and the first mentioned.

her to actuate the control according to the expansion and contraction of the element.

5. In a thermostat,' in combinatiom-an element fr f f n mittin memb ri a dni n si connecting. theginnergend ,of said other, force transmitting member tol'sald' control member at a point intermediate. the ends ofth'e control member, both or said means and the'p'ortion of the control member extending therebetween concording to the forces transmitted thereto by' said force transmitting members to actuate'the control member.

l0. In a. thermostat, in combination, an element adapted to expand and contract under the infiuence. of variations of temperature to which the element is subjected, a control member normally movable a predetermined distance back and forth transversely of the longitudinal center line of the element, means connected by non-articulated stituting'a non-articulated couple operable acjoints to said element and control member opera- 1 tive upon the expansion or contraction of saidelement to actuate the control member, adjusting means cooperating with said element and said means operable to ,eiIect the operation of said means for positioning said means and therebyv the control member for normal operation under any one of a chosen range of temperatures, and means operative manually-for actuating the adjusting means.

11. In a thermostat, in combination, an element adapted to expand and contract under the influence of variations of temperature to'which the movable a predetermined. distance in directions transversely of the longitudinal center line of the element, two oppositely extending transmitting force members having their outer ends connected to said element and their inner ends overlying each: other, a yieldable non-articulated couple connecting the inner ends of said force transmit-. ting members and-the control member and operative to efiect movement of the control memelement is subjected, a control member normally her, meanscarried by said element and cooperating with one of said force transmitting members and operable for adjusting said couple and thereby said .control member for normal operation within any chosen range of temperatures,

' andmeans carried by said element and operative manually for operating the last mentioned means.

12. In a thermostat, in combination, an element adapted to expand and contract under the influence of variations of temperature to which the element is subjected, acontrol member normally movable a predetermineddistance in directions transversely of'the longitudinal center line of the element, a force'transmitting member of less length than-said element arranged substantially parallel with the element and connected at its outer end to oneend of the element, another force transmitting member of less length than said element. arranged substantially parallel with the element and connected at its outer end to the element, a yieldable non-articulated couple between the inner ends of said force transmitting members and the control member for.

effecting movement ofthe control member according to the forces set up in said force transmitting members, and means cooperating with mentioned force transmitting member and controlled manually for adjusting said couple for normal operation within any chosen range of temperatures.

said element and the outer end of the second.-

13. In a thermostat, in combination, a metallic tube adapted to expand and contract in the direction of its length under the influence of variationsoi temperature to which the tube is sub- :lected, a control member in said tube normally movable a predetermined. distance in directions transversely of the longitudinal center line of the tioned force transmitting member and controlled manually for adjusting said couple for normal operation within any chosen range, of temperatures.

14. In a thermostat, in combination, an element adapted to expand and contract under the 1 influence of variations of temperature to which the element is subjected, a-control member nortube, a force transmitting member in said tube mally movable a predetermined distance in direcl and secured at its outer end to one end or the tions transversely of the longitudinal center line tube, another force transmitting member in said of the element, means connected by non-articutube and secured at its outer end to the other end lated joints to said element and control member of the tube, a non-articulated couple between the operative upon the longitudinal expansion or 10 inner ends of said force transmitting members contraction of said element to'actuate the control 10 and control member operable, according to the member, and adjusting means cooperating with forces applied thereto by said iorce transmitting said element and means manually operative to members to efiect the control movement of the adjust the control member, when the expansion control member, andv means cooperating with or contraction of said elementhas been excessive,

15 said tube and the outer end of the second mento move its normal predetermined distance at the 5 temperature which caused said excessive expansion or contraction oi the element.

ROBERT HENRI MAUTSCH.

can-Herons or coneac'rron.

Patent No. 2,061,915; November 24, 1936,

ROBERT HENRI u urscn.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, second column, lines 41 and 42, claim 2, strike out the 'words "movable been and forth transversely of the longitudinal center lineof the element" and in sert the same after "member" and before the comma in line 40, same claim; and that the said Letters Patent should be read with this correction therein that the same may conform to the record. of the case in the Patent Office,

Signed and sealed this 2nd day of February, A. D. 1937.

(Seal) Leslie Frazer Acting Commissioner of Patents.

tionsoi temperature to which the tube is sub- :lected, a control member in said tube normally movable a predetermined. distance in directions transversely of the longitudinal center line of the tioned force transmitting member and controlled manually for adjusting said couple for normal operation within any chosen range, of temperatures.

14. In a thermostat, in combination, an element adapted to expand and contract under the 1 influence of variations of temperature to which the element is subjected, a-control member nortube, a force transmitting member in said tube mally movable a predetermined distance in direcl and secured at its outer end to one end or the tions transversely of the longitudinal center line tube, another force transmitting member in said of the element, means connected by non-articutube and secured at its outer end to the other end lated joints to said element and control member of the tube, a non-articulated couple between the operative upon the longitudinal expansion or 10 inner ends of said force transmitting members contraction of said element to'actuate the control 10 and control member operable, according to the member, and adjusting means cooperating with forces applied thereto by said iorce transmitting said element and means manually operative to members to efiect the control movement of the adjust the control member, when the expansion control member, andv means cooperating with or contraction of said elementhas been excessive,

15 said tube and the outer end of the second mento move its normal predetermined distance at the 5 temperature which caused said excessive expansion or contraction oi the element.

ROBERT HENRI MAUTSCH.

can-Herons or coneac'rron.

Patent No. 2,061,915; November 24, 1936,

ROBERT HENRI u urscn.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, second column, lines 41 and 42, claim 2, strike out the 'words "movable been and forth transversely of the longitudinal center lineof the element" and in sert the same after "member" and before the comma in line 40, same claim; and that the said Letters Patent should be read with this correction therein that the same may conform to the record. of the case in the Patent Office,

Signed and sealed this 2nd day of February, A. D. 1937.

(Seal) Leslie Frazer Acting Commissioner of Patents. 

